Automatic air-valve for steam-radiators.



G. D. HOFFMAN.

AUTOMATIC AIR VALVE FOR STEAM RADIATORS.

APPLICATION FILED MAR. 29, 1913.

Patenfmd Jan. 2, 1917.

fnverziafx I Gea -qe$.%ffman UNITED STATES PATENT oFnroE. GIE'iORG-E D. HOFFMAN, OF PASADENA, CALIFORNIA, ASSIGNOR TO HOFFMAN SPECIALTY COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS;

AUTOMATIC AIR-VALVE FOR STEAM-RADIATOIRS. 1

Specification of Letters Patent.

Application filed March 29, 1913. Serial No. 757,531.

To all whom it may concern:

Be it known that I, GEORGE D. HOFFMAN,

a citizen of the United States, and a resident of Pasadena, in the county of Los Angeles and State of California, have invented certain new apd useful Improvements in Automatic Air-Valves for Steam- Radiators, of which the following is a specification.

This invention is a valve of the type employed for automatically permitting the escape of air displaced in steam radiators by the steam pressure.

To secure successful operation of automatic air valves for radiators, under present day conditions, it is imperative that the device must conform to certain well-recognized standards of measurement; the valve must close automatically when the casing thereof becomes filled with water of condensation from the radiator system; the casing must be completely drained of all water, without ejecting any portion'of the water into the outside atmosphere; and the valve must automatically close'when the water has been drained from the casing, and when all of the air has been ejected and is followed by steam, so that escape of steam is prevented. Heretofore many devices have been placed upon the market, designed to accomplish these results, but such valves as have been produced, appear to be incapable of meeting all of the foregoing requirements. For instance, these valves either do not completely drain themselves of water, or else they become water-logged when the valve casing fills with water. In the instances where the valves do not drain themselves completely, should use of theradiators be temporarily discontinued in cold weather, it is not an uncommon experience for thevalves to freeze and burst. These same valves also accumulate grit and various other impurities carpermit the free escape of air when the water level in the radiator has fallen. A further serious objection to the water-logged valve is that it will only empty itself of the water by reason of the valve being spasmodically permitting the escape of air from the radi ator. The result of all of these conditions is that the'valves perform their functions more or less imperfectly.

The object of this invention is to provide an automatic air valve for steam' radiators,

which will overcome the foregoing objections and meet all requirements, the same Patented Jan. 2, 191 a. i

having provision whereby the air from the radiator, entering the valve casing, is prevented from coming into conflict with the water at any time, the air being compelled to follow a predetermined course, which does I not permit it to come into conflict with the water, thereby overcoming the objections above pointed out. i

The invention consists in the improvements which I will now proceed to describe and claim.

In the accompanying drawings, Figure 1 represents a side elevation of an air valve embodying my invention. Fig. 2 represents a top plan view of thesame. Fig. 3 represents an enlarged section on line 33 of Fig. 2. Fig; 4 represents a section on line t-+1 of Fig. 3.

The same reference characters indicate the same parts in all the figures.

The casing ofmy improved air valve is.

composed of a lower or base member and an upper member, said members detachably connected. The base member comprises a bottom 13 and a circular wall 14 rising from the bottom and internally screw-threaded at 15 to engage an external thread on the upper casing member 16. To the wall 14 of the case member is attached a screw-threaded nipple 17 adapted to engage a tapped orifice in a steam radiator. I

18 represents a tubular member seated at its lower end on the bottom 13 and extending upwardly within the upper casing member 16 above the float 19 hereinafter described. The chief-function of the tubular .member 18 is to form the inner wall of the air ducts. hereinafter described. Said tubu- 1 and having a swlveled ternnnal 21 adapted to project downwardly into the radiator with which the nipple is engaged.

The lower portion of the tubular member 18 is separated from the base wall 11 by an air space 22 which is preferably annular, as indicated by Fig. 3, said air space being wholly outside the float chamber and'communicating with the nipple 17. The air 20 space 22 forms a part of an air conduit extending from the nipple 17 to the upper portion of the casing member 16, entirely outside the float chamber, and adapted to conduct air expelled from the radiator 25 through the nipple along the exterior of the valve chamber to the upper portion of the casing, and to discharge air into the casing below the vent 16 and without permitting the air to carry entrained water to the vent, said conduit being preferably completed by the peculiar formation of the upper casing member 16 next described.

In forming the upper casing member 16 ll emboss or ofise'; a portion or portions thereof, and preferably a plurality of portions, thus forming elongated longitudinal outwardly projecting bosses 21f:- The portions of the member 16 between said bosses are formed to have aclose sliding fit on the cylindrical portion of the tubular member 18 above the casing base, so that the member 16 is rotatable on the member 18 to permit the lower end of the member 16 to be screwed into the base wall 14. The op- 5 eration of securing the member 16 to .the base member therefore converts each boss 24 into an air passage, the inner wall of which is formed by the, member 18.

The lower ends of the bosses 24 communicate with the air space 22, and their upper ends, which are inclined inwardly to form deflectors 25 (Fig. 3) are located .above the member 18 and outside the pe-' riphery thereof, so that entrained water carried by air passing upwardly through the bosses, is deflected inwardly and caused to fall into the upper end of the float chamber as indicated by the arrows, Fig. 3. The member 18 is extended upwardly above the float 19 and forms a chamber which re-' ceives the deflected water, the latter being drained ofl' through the stem 21. There is therefore no possibility of the escape or spitting at the air vent, of water carried by air entering the casing through the nipple 17, because two independent conduits are provided, one for the escaping water and the other for the entering air, each conduit being distinct from the other, so that the water accumulated in the casing E and escaping therefrom cannot be agitated or lifted by the air at the same time entering the casing. In other words, the entering air is compelled to move in one path, and the escaping water is compelled to move in another path, said paths being distinct from each other without interfering or conflicting with each other at any point.

It is obvious that my invention may be embodied in a valve, the upper casing memher 16 of which has but one boss 24: instead of a plurality of bosses. I prefer to provide more than one boss. however, for the sake of symmetry, and for the purpose of distributing the air so that it will not have the same force that it would if delivered by a single boss.

The float is adapted to be raised and caused to close the air vent by water entering the float chamber through the stem 21 when the water is under steam pressure and before it regains its equilibrium. The float is preferably of the expansible hermetically closed type, and provided with a flexible bottom normally resting on a raised portion 5 of the bottom of the casing base, and adapted to be bulged or deflected outwardly by the' expansion, by heat, of a liquid, such as alcohol, inclosed in the float. The deflection of the bottom, which takes place when steam reaches the casing, lifts the float and closes the air vent.

In practice, when the valve is first attached to the radiator, the parts assume the positions illustrated in Fig. 3. During the 5 operation of the radiator system, it is well knowirthat under certain onditions of service, water of condensation surges up and down in the radiator, and as the water goes up into the radiator, air is trapped in the coils and must be drained therefrom before the steam will fill the coils. As long as the water level remains below the lower end of the siphon tube 21', the float will rest upon the bottom 13, and any air within the radia- 5 tor may pass through the nipple 17, air space 22, air passages 2-1:, and finally out through the vent 16. As the water rises in the radiator, it will travel upwardly through the siphon tube 21 and into the float chamber, more rapidly than it will rise in the radiator, because the float chamber is vented through the opening 16. As soon as the water accumulates in the float chamber in suflicient quantity to reach the buoy- 35 ant line of the float, the latter will rise, causing the valve 19 to close the vent 16, so that as the water continues to rise, it cannot be ejected through the vent. If the water rising in the radiator coil should fall before it floods the end of nipple 17, the

gravity of the water column including the siphon 21, draining stem 20 and the water accumulating chamber, will draw air in through the nipple 17 which air will travel upwardly through the channels 24, to a point above the water in the water accumulating chamber, so that justas soon as the float drops, the air can pas out of the vent 16 without having come into conflict with the water at all.

From the foregoing it will be readily understood that the float chamber is usually flooded before'water reaches a level in the radiator that will flood the nipple 17. If"

is so discharged into said water accumulating chamber, any air back of the water will pass out of the vent 16*, just as soon as the float drops, I without carrying any of the water with-it. The vent 16* is of such size that a certain amount of back pressure is created in the casing of the valve when air is escaping through said vent. The weight of the float is such that, assisted by the back pressure, the float will drop just as soon as the water falls below the buoyant line thereof, and the separate air channel through the nipple 17, and conduits 24, serves to keep the pressures in balance, so as to insure the prompt operation of the valve under all conditions.

It will be understood that the pressures at 20 and 22 are controlled by the pressure in the radiator, and that the pressures at these points will'not be materially different at any time, and as long as the vent 16 is open, water may enter tube 20, and air simultaneously enter space 22, both traveling at approximately the same speed.

On other air valves having draining stems it is not uncommon for the air which replaces water flowing from the valve to be free to enter the casing of the air valve through water in the float chamber, and when the valve opens to discharge the air, entrained water is liable to pass out with the air. In my valve the separate air passage wholly outside the float chamber and com' municating therewith above the level of water in the float chamber when-the valve carried by the float is inserted, insures the escape of the air in a. perfectly dry condition;

readily apparent to persons skilled in the art to which it appertains. For instance, as is well known, it frequently happens that a radiator while venting, works water and under this condition the water is liable to surge against the air valve. The float herein described is so constructed that itnecessarily closes, and closes tight against water leakage, andthe valve remains closed as long as water remains against it. The instant water drops away from the valve in the radiator, the siphon automatically discharges the water in the valve back into the radiator, and the valve re-commences venting. It is a well known law in physics that water cannot be discharged from a sealed vessel without being displaced by another body. When the siphon discharges water from the valve herein described, the air passes into the casing through distinct separate passages, provided for it by means of the space between the inner and outer shells which are preferably formed into conduits by the embossed channels, as shown in the drawing. From an inspection of the drawings, it will be readily understood that air entering the valve through the nipple 17, cannot pass through the water in the float chamber, but must pass upwardly outside of the float chamber, between the inner and outer casings. The outlet or outlets for the air conduit, being above the water line in the float chamber, the air passes out ,of the valve perfectly dry and without the slightest spit, because it can never come into conflict with the water. No matter howmany times the water surges against and into the valve casing, the sealed metal float rides the water like a cork, and closes the valve before the slightest drop can get by. It closes and opens as the water comes and goes without the slightest leak, and by reason of the thermostatic construction of the valve, it also promptly and efficiently distinguishes between steam and air, venting all of the air, without permitting the passage of steam. The construction whereby the said air conduit is provided may be variously modified, and the conduit may have one outlet into the casing, such as that provided by a single boss 24, or a plurality of such outlets.

What I claim and desire to secure by Letters Patent is:

1. An air valve'for steam radiators comprising a casing having an air outlet in its upper portion, a nipple connected with the lower portion of said casing, a water accumulating chamber within said casing, a

- float within said water accumulating chamber and provided with a valve for closing said air outlet, a siphonic drainage tube leading from the lower portion of said water accumulating chamber and connected therewith to prevent passage of water from the chamber except through said tube. and an air conduit having a lower inlet end communicating with the nipple. and an upper end in connmmication with said water accumulating chamber at a point above any possible level of the water within the water accumulating chamber when the valve carried by said float is unseated.

2. An air valve for steam radiators comprising a casing having an air outlet in its upper portion, a nipple connected with the lower portion of said casing. a water accumulating chamber within said casing, a float within said water accumulating chamber and provided with a valve for closing said air outlet, and a siphonic drainage tube leading from the lower portion of said water accumulating chamber and connected there to to prevent passage of water from the water accumulating chamber except through said tube, the wall of said water accumulating chamber, and the wall of the casing cooperating to form an air conduit having a lower inlet end communicating with the nipple and having its sole air discharge portion in communication with said water accumulating chamber at a point above any possible level of the water in said water accumulating chamber when the valve carricd by said float is unseated.

3. An air valve for steam radiators comprising a lower or base casing member having a bottom, a vertical wall, and aradiatorengaging nipple-projecting from said wall,

a cylindrical tubular member seated on the base and forming therewith a float chamber open at its upper end and havin a draining stem extending through the nipp e, the lower portion of the float chamber being separated from the wall of the base member by an air space communicating with said nipple, an upper casing member detachably connected with the wall of the base member, and having an outwardly projecting longitudinal boss on its upper portion extending from said air space to a point above the float chamber, the internal surface of the upper casing member at opposite sides of said boss being formed to have a close sliding fit on the external surface of the float chamber, so that the boss and the said air space form an air duct entirely outside the float chamber and communicating with the nipple, the upper end of the upper casing member being contracted and prov1ded with an air vent,

and a float movable vertically in the float chamber and provided with a valve adapted to close said air vent.

4. An air valve for steam radiators comprising a lower orbase casing member having a bottom, a vertical wall, and a radiabeing separated from the wall of the base member by an annular air space communicating with said nipple, and an upper casing member detachably connected with the wall of the base member, and having a plurality of outwardly projecting longitudinal bosses on its upper portion extending from said annular air space to points above the float chamber, the internal surface of the upper casing member at opposite sides of the bosses being formed to have a close sliding fit on the external surface of the float chamber, the upper end of the upper casing member being provided with an air "cut and the float chamber with a float having a valve adapted to close said vent.

5. An air valve for steam radiators comprising an external casing having a radiator-engaging nipple at its lower portion and an air vent at its upper portion, a float chamber within said casing having an open upper end, a draining tube having an air tight connection with the lower portion of the float chamber and extending through said nipple without communicatin therewith, a float movable in the chem er and havin a member adapted to close said vent, the v, ve being provided with an air conduit wholly external to the float chamber, and

extending from the nipple to the upper por tion of the casing, having a discharge end communicating with the float chamber at its upper portion, the float chamber forming one wall of said conduit and preventing air entering the casing through the nipple from passing through water in the float chamber.

6. An air valve for steam radiators comprising an external casing having a radiator-engaging nipple at its lower portion and an air vent at its upper portion, a float chamber within said casing having an open upper end, a draining tube having an air tight connection with the lower portion of the float chamber and extending through said nipple without communicating therewith, a float movable in the chamber and having a member adapted to close said vent, the valve being provided with an air conduit wholly external to the float chamber, and extending from the nipple to the upper portion of the casing, said conduit being adapting extended upwardly to form a space above the float and out of the path of air risin a casin havin an air outlet in its upper portion, a nipple connected with the lower portion of said casing, a water accumulating chamber within said casing, a float within said water accumulating chamber and provided with a valve to close said air outlet, a drainage tub'e communicating with said water accumulating chamber through an opening adjacent the bottom thereof and having a down turned discharge end, said tube being connected with said chamber to I prevent passage of water from the chamber except through the tube, and an air conduit having a lower inlet end communicating with the nipple, and having an upper end in communication with said water accumulating chamber at a point above any possible level of the water within said water accumulating chamber when the valve said float isunseated.

V In testimony whereof I have affixed my signature in presence of two witnesses.

' GEORGE D. HOFFMAN. lVitnesses:

C. F. BROWN, P. W. PEZZE'I'1I.

carried by 

